JP2728303B2 - Disc player tray loading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for turning an optical disc (eg, video disc, compact disc, etc.) on a disc player in order to record and reproduce the disc on a disc player. The present invention relates to an apparatus for loading a tray for transferring a sheet to a table position.

[Prior Art] Conventionally, as a tray loading device as described above, a gear rotated by a motor is meshed with rack teeth formed on the tray, and the tray is drawn into a disk player by controlling the rotation of the motor. Or was pulling out.

As a method of controlling the rotation of the motor, there is a method described below.

(A) A method of arranging switches at the tray pull-in and the end position of the drawer, applying a constant voltage to the motor until the switch is turned off, and driving the tray at a constant speed.

(B) arranging a switch at a position at which the tray is pulled in and at the end of the drawer, and arranging another switch at an intermediate position of the drawing and drawing separately from the switch;
A constant voltage is applied to the motor until the other switch is turned on, and when another switch is turned on, the voltage applied to the motor is reduced to a constant low voltage until the switch at the end position is turned off, and the tray is moved at a constant low speed. How to drive.

(C) A switch is arranged at the same terminal position as in the method (a), a constant voltage is applied to the motor for a certain period of time, and the voltage applied to the motor is pulse width until the switch is turned off after the certain period of time. A method of driving the tray so that the speed of the tray is gradually lowered by modulating it gradually.

[Problems to be solved by the invention]

By the way, in the control method (a) described above, since at least two switches are required, the number of parts is large, the cost is high, and the tray is in vigorous contact with the stopper at the tray pull-in position and the pull-out position. Therefore, there is a problem that a loud impact sound is generated.

Further, in the control method (b) described above, the speed at the final position of the retraction and withdrawal is lower, so that the impact sound is smaller than that in the method (a) described above.
Since the number of switches for deceleration is increased by one, the number of parts is increased and the cost is further increased as compared with the method (a), and the speed is rapidly changed. There was a problem of doing.

Further, in the control method (c) described above, the moving speed when the tray stops is further slower than that in the method (b) described above, so that there is an advantage that the impact sound is further reduced. However, if the mechanical load changes due to a change over time or variation in the mechanical part, the speed of the tray at the time of deceleration changes, so that the speed of the tray when the switch at the end position is turned off also changes. Therefore, there is a problem in that when the pulse width modulation is performed according to the mechanical load, the circuit configuration becomes very troublesome.

[Object of the invention]

An object of the present invention is to solve the above-described problem, and an object of the present invention is to keep the time for driving the tray in a decelerating state constant even when the mechanical load changes due to aging or variation in the mechanical part. Therefore, it is desirable to provide a tray loading device for a disc player in which control can always be performed in a constant deceleration state and the speed when the tray stops is always constant.

[Summary of the Invention]

A tray loading device for a disc player according to the present invention achieves the above-mentioned object, and the gist of the invention is that a loading motor circuit speed control means capable of deceleration control from a constant speed; It has a timer for measuring the time from start to completion, and a control circuit for calculating the time for controlling the motor at a constant speed based on the time measured by the timer.

(Example of the invention)

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a loading motor for moving a tray to a retracted position and a retracted position, and 2 denotes a motor for driving the motor 1 by pulse width modulation. A motor drive circuit for detecting the end position of the tray 1 and a switch for detecting the end position of the tray disposed at the end position where the tray 1 is pulled out and 5; , A compact disc, a single disc, etc., and outputs an output according to the size of the disc (for example, Japanese Patent Application No. 1-2221706 filed by the present applicant). Means 6, a tray moving direction discriminating means for outputting an output indicating whether the tray 1 is in the pull-in direction or the pull-out direction, 7 is a timer, 8 is a memory, and 9 is FIG. A control circuit for operation as a flowchart.

Next, the operation will be described with reference to the flowchart of FIG. 2 and the operation characteristic diagram of FIG. 3 based on the above-described configuration.

First, when an eject operation or a play operation is performed, the control circuit 9 determines whether the tray moves in the pull-in direction or the pull-out direction by the output from the tray movement direction discriminating means 6 which is the eject operation or the play operation. (Step S1). The reason for determining the moving direction of the tray is that the center of gravity of the tray differs in the moving direction of the tray, the load applied to the motor 1 changes, and the loading time changes.

Subsequent to the operation of determining the moving direction of the tray, the size of the disk is determined based on the output from the disk type determining means 5 (step S2). Here, the disc size is determined because the weight varies depending on the disc size, the load applied to the motor 1 changes, and the loading time changes.

Then, the control circuit 9 calculates a preset time for controlling the motor 1 at a constant speed from a memory, taking into account the above-described tray moving direction and the type of disk, and rotates the motor 1 at a constant speed. determining the time t _f for (step S3). The time t _f and is determined the control circuit 9 is sent to output a constant voltage for rotating the motor 1 at a constant speed relative to the motor drive circuit 2 (step S4). Therefore, the motor 1 starts rotating at a constant speed,
The tray is loaded at a constant speed.

In this state, the control circuit 9 monitors whether the time tf has elapsed (step S5). _If the time tf has not elapsed, the process returns to step S4.
Is turned on (step S6). Subsequently, the control circuit 9 causes the motor drive circuit 2 to output pulse width modulation such that the rotation speed of the motor 1 gradually decreases (step S7). Therefore, the motor 1 continues to rotate while gradually decreasing the rotation speed, and the tray is loaded while gradually decreasing the speed.

During this loading operation, the control circuit 9 monitors whether or not the end position detection switch 3 or 4 is closed (step S8). If steps 3 and 4 are not closed, the process returns to step 7, and the switch returns to step 7. When the closing of 3, 4 is detected, the time of the timer 7 at that time is read (step S9). The time at this time is _defined as tp. Then, the control circuit 9 monitors whether the time t _p is preset, or equal to the target value previously detected (step S1
0) If the values match, the operation is terminated without rewriting the contents of the memory 8, and if they differ, it is monitored whether it is longer than the target value (step S11).

When longer than the target value, a time obtained by adding the excess time period Δt the time t _f is stored in the memory 8 as a new target time t _f (step S12), the addition, shorter than the target value In this case, the short time Δt is set to the time t _f
It is stored in the memory 8 more subtracting the time as a new target time t _f (step S13), and it is an objective reference time t _f of the next loading. Accordingly, the time for controlling the motor 1 while gradually decelerating is always kept constant, and the change in the speed of the tray due to the difference in load is driven by changing the time for controlling the speed at a constant speed. The deceleration speed is always constant without being affected by the load.

〔The invention's effect〕

As described above, according to the present invention, the time for controlling the tray at a constant speed is varied in order to absorb the change in the load applied to the motor. Since the state is the same, the tray can be reliably pulled out and pulled in. In addition, there is no impact noise for the tray to come into contact with a stopper, etc., and there is no need for a speed switching switch. It has an effect that it can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart of the above embodiment, and FIG. 3 is a characteristic diagram of a tray moving state. 1 ... motor, 2 ... motor drive circuit, 3,4 ... end position detection switch, 5 ... disc type discriminating means, 6
... Tray moving direction discriminating means 7 timer 8
Memory 9, 9 Control circuit.

Claims (1)

(57) [Claims] 1. A loading motor rotation speed control means capable of deceleration control from a constant speed, a timer for measuring a time from the start to the completion of the deceleration, and a constant motor based on the time measured by the timer. A tray loading device for a disc player, comprising: a control circuit for calculating a time to be controlled by a speed.